IntlChar::isUUppercase() function in PHP

The IntlChar::isUUppercase() function checks whether the given input character is an Uppercase Unicode character or not.

Syntax

IntlChar::isUUppercase(val)

Parameters

• val − It is a character value, which is encoded as a UTF-8 string or Unicode codepoint integer.

Return Value

The IntlChar::isUUppercase() function returns TRUE if the val is an Uppercase Unicode character, FALSE otherwise. Returns NULL if the input is invalid.

Example 1

The following example demonstrates basic usage with different character types ?

<?php
    var_dump(IntlChar::isUUppercase("2"));
    echo "<br>";
    var_dump(IntlChar::isUUppercase("Jack"));
    echo "<br>";
    var_dump(IntlChar::isUUppercase("K"));
?>

bool(false)
NULL
bool(true)

Example 2

Let us see another example with special characters and lowercase letters ?

<?php
    var_dump(IntlChar::isUUppercase("*"));
    echo "<br>";
    var_dump(IntlChar::isUUppercase("n"));
    echo "<br>";
    var_dump(IntlChar::isUUppercase("D"));
?>

bool(false)
bool(false)
bool(true)

Key Points

• The function only accepts single characters − multi-character strings return NULL
• Numbers and special characters return FALSE
• Only uppercase Unicode letters return TRUE
• The function supports international Unicode uppercase characters

Conclusion

IntlChar::isUUppercase() is useful for validating single uppercase Unicode characters. It returns TRUE only for uppercase letters and FALSE for all other character types including numbers and symbols.